OBJECTIVE To review the scientific literature on and evaluate studies of face-to-face counseling for the promotion of exclusive breast-feeding. SOURCES OF DATA Three databases were reviewed for the 1990-2001 period: MEDLINE, Latin American and Caribbean Health Sciences ("LILACS"), and the Cochrane Library. We selected studies describing face-to-face counseling with mothers during only the postnatal period or both the pre- and postnatal periods. Studies describing interventions only during pregnancy were not considered. We classified the selected studies using a modification of the criteria of Downs and Black for assessing the methodological quality of studies of health care interventions. RESULTS Nineteen studies were included. The duration of follow-up, type of intervention performed, and ethnic, socioeconomic, and reproductive characteristics of the groups studied varied widely. In terms of limitations, the most frequent ones were an inadequate description of confounding factors and of the characteristics of the sample, poorly documented methodology, and no adjustment for confounding factors. Seventeen studies reported a beneficial effect of the intervention, although the magnitude of this effect differed widely across the various studies. Two studies reported a dose-response effect, with the impact being directly proportional to the number of counseling sessions. Only one study reported no effect of the intervention on exclusive breast-feeding, at 3 and 5 months postpartum; of the 19 studies assessed, this one had the smallest number of counseling sessions, just one or two. CONCLUSIONS Face-to-face counseling, given during different time periods, led to significant changes in the rate of exclusive breast-feeding. Our analysis suggests that the support to the mothers must continue after hospital discharge and must include guidance on breast-feeding techniques and ways to resolve problems that occur.